Error 1602 on VAZ cars: causes and how to fix

Error P1602 on cars of the Lada Vesta family signals a one-time or repeated loss of supply voltage. This type of error is not displayed on the dashboard using a special LED, as a result, it can only be detected by connecting using diagnostic equipment.

Error P1602 can occur even during normal use of the vehicle, for example, when the terminal is reset from the battery. In such cases, this error only indicates a single voltage loss, which does not entail any serious consequences. However, in order to clarify what exactly caused this code, you need to reset the errors using a diagnostic device and monitor its possible occurrence for several days. If the error reappears, and you did not open the car’s power circuit in any way, then the problem lies in one of the components of your car and requires a solution.

• Fuse F70 (60A)
• Controller
• Power circuit

The error is detected by the dealer using the following algorithm: first of all, the integrity of fuse F70 is checked; if it is intact, proceed to check the power circuit. The cable harness block is disconnected from the controller, after which the car’s ignition is turned on and contact “X1.1/A5”, which is connected to ground, is checked using a probe. If the result is negative, proceed to checking the circuits connected to the ignition switch and the controller.

If the result is positive, the car’s ignition is turned off again, the harness block is reattached and the diagnostic device is reconnected. In the program, select the “Signal monitoring” section; ADC Battery Voltage” and measure the voltage of the on-board network; if the device shows that the network voltage is close or even equal to the battery voltage, then there is no malfunction as such.

In cases where the network voltage differs significantly from the battery voltage, the main relay is removed and the harness contacts to terminals 85 and 30 are checked using a probe. If the probe light does not light up on one or two contacts at once, then the network break is coming from them. If both contacts are working properly, then using a probe, connect the harness contacts to terminals 85 and 86 and the relay; a non-lit probe light in this case indicates an open circuit in the control circuit of the main relay or a malfunction of the controller itself.

If the probe light comes on again, then the contacts of the harness block are connected using a jumper to terminals 30 and 87, after which they look at the test result in the diagnostic apparatus. In cases where the device shows a network voltage close to the battery voltage, the culprit of the error is an unreliable connection or a malfunction of the main relay. If the voltage still cannot be even closely compared with the battery voltage, then the cause of the error is faulty cables that connect the main relay to the controller contacts “X1.1/L3” and “X1.1/K3”, fuse F70 or the controller itself.

Error p1602 stands for “Control system controller, board voltage interruption.” In practice, this means that somewhere in the car’s electrical network a contact has disappeared, most likely a “minus” one. Most often, error p1602 occurs on domestic VAZ cars, starting from the tenth model (VAZ-2110) and higher - on Kalina, Priora. The difficulty of diagnosis lies in the fact that the electronic scanner is not able to show in which particular area or specific device the on-board voltage has disappeared. Therefore, localizing the location of a breakdown sometimes takes a lot of time and effort.

What does error code p1602 mean?

Error p1602 means that the electronic control unit (abbreviated as ECU) lost power for some time. At the same time, it is important to distinguish whether it disappeared in emergency mode or was authorized. It is also possible that problems arise in certain areas of the machine’s electrical wiring, causing the power to be lost to the control unit. For example, this could be a relay, battery, generator, broken wires, overload of the electrical system by consumers, and so on.

In most cases, error code p1602 is harmless and does not affect the behavior of the machine. In this case, the Check Engine light on the dashboard does NOT even activate. The “controller voltage interruption” error can occur even when simply removing the negative terminal from the battery to reboot the electronic control unit, but not always (depending on the car, ECU firmware, and so on).

In some cases, it is noted that the car has difficulty starting, especially in cold weather. Therefore, it is advisable to diagnose a breakdown as early as possible, since any minor malfunction can cause significant wear and tear on other engine elements, including expensive ones.

It happens that with such an interruption in the power supply to the electronic control unit from the on-board electrical network, data from the RAM is lost. Then a situation arises when up-to-date information about the lambda probe, knock sensors, misfires, idle speed and others disappears from its memory. Accordingly, after restoring power to the controller, it may generate errors associated with the engine elements listed above. Then the codes should be cleared and when they are entered again, you will need to check the power circuit from the battery to the controller. In VAZ cars this is contact No. 18.

Power surge on board network

Niva Chevrolet error 2196

Common errors when switching from gasoline to gas in a Chevrolet Niva equipped with gas equipment: 0328 (knock sensor circuit, high signal level) and 2196 (oxygen sensor to the converter, over-enriched mixture).

The appearance of errors is due to the fact that when switching from gasoline to gas, the engine control unit uses the same firmware, which implies operation on the same type of fuel. Gasoline and gas form different fuel-air mixtures, which produce different parameters when burned. The engine control unit has the ability to automatically adapt to changed fuel parameters, but when switching to gas, its capabilities may be exceeded, as a result of which errors appear. It is recommended to use one type of fuel constantly or change the firmware of the control unit.

Every modern car owner knows about the existence of an on-board computer, which can not only indicate the basic parameters of the operating mode (speed, consumption, temperature), but also recognize errors caused by various malfunctions. Unfortunately, Chevrolet Niva error codes cannot be deciphered without additional tables, since there are too many of them. Let's consider various diagnostic methods.

We receive the first signal about the presence of a malfunction using the indicator on the “Check-Engene” panel.

After turning on the ignition, all systems are tested, and if no errors are detected, this indicator goes out. Otherwise it remains burning. Specialized centers will quickly identify the error and not for free, but the Chevrolet Niva has a built-in on-board computer that can allow you to deal with the problem yourself.

Self-diagnosis

Without going into details of the operation of all electronics, we note that the functioning of all vehicle systems is “monitored” by an electronic control unit (ECU).

It receives information from numerous sensors. Like any computer, the ECU requires software called firmware. This firmware is capable of analyzing indicators received from sensors, comparing them with normal parameters, identifying errors and storing these errors in memory.

Carrying out self-diagnosis

In the Chevrolet Niva, as in some other cars of the VAZ family, some parameters can be displayed on the VDO dashboard. It is often called an integrated on-board computer.

Testing is started by first pressing the daily mileage reset button and simultaneously turning the ignition key.

All instrument needles begin to move, which indicates the beginning of the testing process. Pressing the same button once will cause the firmware version to appear on the display, and pressing it again will give us a reading called an error code.

Panel codes should not be confused with ECU codes, which are diagnosed by external devices.

The operation of the on-board computer cannot be called flawless, since many errors arise as a result of software failure. You have to reset the errors by holding down the daily mileage reset button in testing mode. This diagnostic method is not entirely convenient for the reason that the error code can be the result of the sum of two codes at the same time (10=8+2).

Diagnostics with a scanner

The information in this section is quite extensive, since there are many types of scanners.

The basic principle of their operation is that all data, including errors, is transmitted from the ECU to a special diagnostic connector, which in a Chevrolet Niva is located on the driver's side under the steering wheel.

Possible reasons

The manual for VAZ cars directly states that the conditions for the formation of error 1602 are:

• the ignition must be turned on;
• The controller (ECU) has detected a loss of data in memory.

There are many reasons why error code p1602 is generated in the memory of the electronic control unit. Without going into details, first we will briefly list those components, assemblies and contacts, the failure of which can lead to a loss of voltage in the controller circuit and an ECU error. So:

• Accumulator battery. There may be a bad contact (on the “plus” or “minus”), or simply a poorly charged battery. Alternatively, the battery capacity is not enough to power a large number of powerful electricity consumers (for example, an electric winch, a large amount of additional lighting). Also, such an error may occur when the battery was completely disconnected from the car (for example, the battery was replaced with a new one). Another option is an old and/or not fully charged battery; an error may occur when starting the engine on a discharged battery.
• Car generator. There may be problems with the electrical power it produces, or loss of contacts on it. Including the loss of ground, which is a fairly common cause of error 1602 for the VAZ 2114, Priora and Kalina.
• Signaling. Some car alarms, when the car is armed, forcibly disconnect the battery from the engine so that attackers cannot start the engine when opening the interior. “Smart” electronics regards this step as an error, forming it in the ECU memory.
• Short-term voltage drop. The drop could be caused, for example, by starting the engine in severe frost, when a lot of energy from the battery was used to start the starter, and the ECU was left without electricity for a short time, which caused the corresponding error 1602 to be generated.
• "Mass" of the ECU. This is a fairly common reason when the corresponding contact is oxidized or interrupted. In this case, the electronic control unit considers itself de-energized with all the ensuing consequences.
• Ground connection between the body and the engine. The reason for this may be mechanical damage to the wire, oxidation of contacts, displacement or dismantling of the engine (during repairs or an accident).
• Fuse box. Often the contacts on them oxidize, which causes a drop in the voltage going to the corresponding elements from the fuse-links. In addition, the problem may be in the block itself.
• Electronic control unit. There may be a software or hardware failure. It is better to solve the problem in a car service center.

There are cases when, after self-flashing, the electronic control unit begins to fail and generate false errors, including 1602.

Other automaker definitions for P1602

• Engine Control Module (ECM) Anti-lock Braking System (ABS) / Traction Control System (TCS), CAN Data Bus - Communication Failure (GM).
• Battery Voltage Monitor - Malfunction (Toyota).
• Engine Control Module (ECM) - Low Battery Voltage (Volkswagen).
• Engine control module (ECM) - low battery voltage (Audi).
• CAN Data Bus - Anti-lock Braking System (ABS) / Traction Control System (TCS) (Buick).
• CAN Data Bus - Anti-lock Braking System (ABS) / Traction Control System (TCS) (Cadillac).
• CAN Data Bus - Anti-lock Brake System (ASS) / Traction Control System (TCS) (Chevrolet).
• Engine Control Module (ECM) Unprogrammed (Chrysler).
• Engine Control Module (ECM) Unprogrammed (Dodge).
• Transmission Control Module (TCM) - Serial Communication Problem (Hyundai).
• ECM communication with ABS - circuit malfunction (Isuzu).
• Engine Control Module (ECM) Unprogrammed (Jeep).
• Transmission Control Module (TCM) - Communication Lost (Kia).
• Battery voltage monitoring - malfunction (Lexus).
• Immobilizer control module/engine control module (ECM) - communication error (Mazda).
• ECM for LSI system - communication failure (Mitsubishi).
• CAN Data Bus - Anti-lock Brake System (ABS)/Traction Control System (TCS) (Oldsmobile).
• Engine Control Module (ECM) Unprogrammed (Plymouth).
• CAN data bus. Engine Control Module (ECM) Anti-Lock Braking System (ABS)/Traction Control System (TCS) - Signal Malfunction (Pontiac).
• Engine control module (ECM) - faulty (Saab).
• CAN Data Bus, Anti-Lock Brake System (ASS), Traction Control System (TCS) to Engine Control Module (ECM) - Lost Communication (Saturn).
• Engine Control Module (ECM) - Programming Error (Subaru).
• Electronic Throttle System (ETS), Throttle Return Spring - Malfunction (Volvo).

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Elimination methods

Methods for eliminating error p1602 directly depend on the reason why it was formed in the memory of the electronic control unit. However, before performing the steps listed below, it makes sense to programmatically reset the error. If there are no visible breakdowns, then it is quite possible that the error “Court Controller, loss of supply voltage” was generated accidentally.

We list possible solutions to the problem in the same sequence as the reasons that caused them:

• Battery. Use a normally charged battery that holds a charge well and also has the appropriate capacity suitable for a particular vehicle (this is especially true for winter, when difficult engine starts are expected). Periodically check the charge level, electrolyte density, the quality of the terminal contacts on the battery, and if necessary, clean and lubricate them. Clean the contacts on the wires in the same way. If possible, you can check the battery leakage current. Sometimes an action that helps get rid of the error is to remove the negative wire from the battery for about 5 minutes (a few seconds is not enough), and then quickly put it on and set it in such a way as to ensure tight contact between the wire and the battery terminal. It is also advisable to first clean and lubricate the contact.
• Generator. It makes sense to double-check the operation of the diode bridge, check the voltage at the terminals (on most modern passenger cars the corresponding value should be about 13.7...14.0 V). Check the ground of the generator and, if necessary, inspect the wire and corresponding contacts. Similarly, clean all accessible contacts on the generator, as well as tighten them. You can also re-stripe the wires and make new contacts to improve their quality. Clean the base of the generator mount and the engine block at the point of contact. In some cases, tightening the alternator belt helps (especially if it slips and whistles); if the belt is significantly worn, it is better to replace it with a new one. In rare cases, the generator is completely replaced.
• Signaling. Regarding the alarm system, it is advisable to consult with the employees who installed the alarm system on the car, or find documentation for it on the Internet and find out whether it disconnects the battery from the system as protection or not. If yes, then you will have to come to terms with this error, or, as a last resort, change the alarm system to another one without a similar function.
• Short-term voltage drop. Usually in this case, this error is simply reset programmatically from the ECU memory. It should not be restored in the future.
• "Mass" of the ECU. Check the quality of the ground; if it is damaged, restore the integrity of the contact and/or wire. The chip may be damaged.
• Ground connection between the body and the engine. Inspect the wires and contact connections; the tips (if any) may be damaged. If necessary, test the wire with a multimeter to check for continuity or damage to the insulation. If the wire is broken or damaged, it must be replaced with a new one. In this case, it is advisable to use tips.

• Fuse box. Check the contacts in the block. Moreover, both coming from the battery and internal ones, directly on the fuses themselves. If necessary, tighten the contacts, remove oxides, and lubricate. It is especially necessary to check the fuse that goes to the electronic control unit, as well as its seat, the quality and cleanliness of the contact, and if necessary, inspect and clean it. It is also advisable to check the condition of the contacts in a special block under the hood. To do this, it is better to use a special contact cleaner.
• Electronic control unit. If there is such a possibility, it is advisable to install an ECU of the same model with the same firmware version on the car. At the same time, check whether voltage is coming to the supply terminal of the control unit and what its value is. However, it is best to seek help from official dealers or a car service that repairs electronic “brains,” since reflashing or changing settings yourself can be fraught with big problems.

As practice shows, error 1602 itself is in most cases harmless, and the car owner finds out about it only when he uses a scanner to remove information from the ECU along with other errors or there is an on-board computer with a screen on which the relevant information is displayed. Therefore, if it does not affect the behavior of the machine (and in most cases this is the case), then the machine can be used and “bothered” about it. As for elimination, the cause is usually poor ground or battery contact.

Error P1602 is diagnosed on cars when one of the on-board voltages is not supplied to the engine control unit (ECU). Various options are possible: both permanent absence and short-term outages (one-time or periodic).

As a rule, the control unit receives voltage via several buses:

• 30 bus – on-board network voltage, which operates constantly, parallel to the positive terminal of the battery;
• 15 bus – on-board network voltage through the ignition switch (relay);
• 50 bus – on-board network voltage supplied when the “engine START” key is turned on.

In this case, the engine control unit can receive direct power from various contacts of the ECU connector. Thus, monitoring the voltages supplied to the engine control unit is difficult in the absence of a circuit diagram. Depending on which power supply is missing, the vehicle may behave differently with the same P1602 error.

The most characteristic symptoms:

• the ignition does not turn on;
• the ignition turns on, the starter does not start;
• the ignition turns on, the starter operates when the engine starts, the engine does not start;
• the ignition turns on, the engine starts, does not respond to the accelerator pedal or other controls;
• the ignition is turned on, the engine starts, there is color music on the dashboard (indicator lights blink, dial gauges deviate chaotically);
• The car is operating normally, the error is diagnosed.

Error P1602 does not necessarily indicate a complete lack of voltage at one of the power inputs. The battery may have been discharged to a critical level or was temporarily disconnected from the terminals. After connecting the battery, error P1602 remains in the memory of the control unit, and it is enough to delete it (erase from memory) for the engine ECU to exit the emergency mode.

Decoding P1602

• Low voltage supply to the engine control unit (AUDI, ISUZU, SAAB, VOLKSWAGEN).
• Knock Sensor Module Performance (BUICK, CADILLAC, CHEVROLET, GMC).
• Speed ​​Control Solenoid (DODGE) Circuit.
• Problem with the wiring of the engine control unit (HYUNDAI, KIA).
• Engine control unit immobilizer error (MAZDA).

Where is the P1602 sensor located?

The image above shows the ECU connector of an Audi Q7, terminal 30 is circled.

It should be noted that this code does not refer to the voltage at terminal #30 as shown here, but to the various and multiple terminals in the connector that should have a certain voltage across them when the ignition is turned off. Therefore, the presence or absence of power at terminal No. 30 (as shown here) when the ignition is turned OFF should NOT be taken as evidence of failure or malfunction unless the manual for the vehicle in question explicitly states that the specified voltage should or should not (depending on depending on the circumstances) be present at this terminal when the ignition is turned off.

Operating principles of the on-board computer

The electronic control unit of the VAZ 2114, as on other cars, is primarily designed to monitor the condition of various components and assemblies, as well as for subsequent indication of breakdowns if they occur. The introduction of the concept of self-diagnosis is a sound decision designed to facilitate both the operation of the car for the driver and possible repairs for the car service center.

The system works simply: if a unit breaks down or there is no signal from it, the ECU displays a coded message on a small display, which can be deciphered using the appropriate car manual.

Alas, as often happens with the domestic auto industry, the electronic brains of the ECU may begin to fail for one reason or another, giving the VAZ 2114 error 1602 in situations where there is no real breakdown. At the same time, the problem cannot be ignored under any circumstances, because once out of ten the control unit can signal that there are actually problems in the system.

Instead of immediately going to a service center and paying money for diagnostics, experts recommend trying to find out the cause of error 1602 on your own - it is quite possible that even an inexperienced car owner will be able to solve the problem.

It is important to remember that first of all, you should exclude the possibility of an error in the operation of the ECU itself and sensors if any error is detected on the screen. It will be useful to buy only original electronics parts in advance when operating a car, and not install cheap analogues (the same is true for unlicensed firmware).

As for the general list of reasons that can alert the ECU with a problem message, the most common factors are:

1. Changing the type of fuel system without flashing the controller.
2. Low quality fuel, which has a complex effect on the entire energy system.
3. Clogged air or fuel filter.
4. Inept attempts to reconfigure the “brains” of the controller.
5. System failure of the ECU or failure of one of the sensors.

Do not forget that any intervention in the factory settings of the computer or replacement of sensors (as well as cables and connectors) with unofficial ones, not produced by AvtoVAZ, is fraught with frequent errors in the operation of the ECU - as a result, this means lost nerves and money in the future.

A little about codes

A big problem with VAZ products is imperfect self-diagnosis. Very often, even fairly simple faults related to the battery or generator are presented as a serious breakdown of the power plant. For this reason, you should not rush to a car service for repairs. Initially, you need to try to identify the malfunction yourself and, if it is not particularly serious, fix it on the spot.

It is known that in most cases the codes are related to the readings of sensors installed on the car, which are essentially the eyes and ears of the on-board computer. Therefore, first of all, you should make sure that the control devices are working properly.

The problem, however, is greatly aggravated by the following - quite often the codes issued have nothing to do with the breakdown that occurred. In particular, this happens too often in cars manufactured by VAZ.

However, according to professionals, this happens largely due to the installation by car owners of components produced unofficially. However, the sensors themselves remain fairly simple devices, from which you should not expect high accuracy in any case.

Meanwhile, not everyone can afford to use spare parts produced exclusively by official suppliers. Many note that in most cases their prices are clearly inflated.

The following reasons may cause the ECU to issue a particular error code:

• failure of one of the sensors while maintaining the functionality of the node it controls;
• low-quality fuel, poorly flammable - this leads to improper operation of the power plant;
• clogging of both air and fuel filters;
• incorrect flashing of the controller with homemade software;
• a failure occurred in the ECU itself (as practice shows, this problem occurs most often);
• transferring the car to gas, without replacing the on-board computer program.

Moreover, many VAZ-2114 owners do not consider it necessary to refuel their car at branded gas stations and prefer cheaper options, because they know that the engine of their car can easily cope with the lowest quality fuel. However, the ECUs in the VAZ are too delicate and are not ready to silently tolerate this state of affairs.

In this case, it often turns out that when flashing, they install the latest software, which contains several hundred codes, which are often displayed inadequately.

Possible reasons

When diagnosing error P1602, the engine control unit is insufficiently powered from the on-board network. What could be the reasons:

• temporary disconnection of the battery terminals (terminals) from the on-board network for the period of repair or maintenance;
• critically low battery charge;
• voltage dips in the on-board network during engine startup with low residual battery capacity (for example, during engine startup at extremely low ambient temperatures);
• fuse blown in the power supply circuit;
• fraying of contacts or malfunction of relays servicing the engine control unit;
• contact failure of the control unit connector;
• abnormal operation of car alarms;
• error on the CAN bus (communication bus between control systems);
• problems with the generator;
• violation of the common wire (ground) of the car;
• control unit malfunction;
• previous polarity reversal when installing the battery.

Alternator belt problems

Everything is simple here. When the belt is loose, the generator can rotate without problems without load, but when it appears, it simply stops. As a rule, quite often with such a breakdown a characteristic belt whistle is heard. Accordingly, correct tension adjustment or replacement of a stretched alternator belt eliminates the problem.

Similar miracles can also happen even if the belt is new and well tensioned. For example, in wet rainy weather, due to design flaws in the engine compartment, water gets between the generator pulley and the belt. It works like a lubricant. As a result, the belt simply slips along the pulley, and the driver sees wild voltage drops in the on-board network on the voltmeter.

If engine oil is leaking from all the cracks, so to speak, it won’t be long before it ends up on the generator pulley or belt. The result should already be expected and understandable. By the way, about rainy weather and water. When it rains, what do we do? That’s right, we turn on the stove so that the windows don’t sweat, as well as the headlights, fog lights, etc. so that we can be seen on the road. And this is all the load on the generator, due to which even just a little water on its pulley will lead to belt slipping

Please take this into account and pay attention if necessary.

Error 1602 on VAZ cars: what is the reason

If you look through the VAZ manuals that came with the car, you will find information in them that this malfunction can only occur under the following conditions:

• With the ignition off;
• If the controller notices that some data has been lost.

This problem occurs on almost all relatively new VAZ models, for example:

• Priora;
• Grant;
• VAZ 2110;
• VAZ 2112;
• VAZ 2114;
• Kalina;
• Niva Chevrolet;

It’s difficult for me to immediately see all the reasons for error P1602. I will try to talk about the main ones. I will describe the problem using the example of individual units in which an error can most often occur:

1. Battery. It may be discharged or you have poor terminal contact. I once had a problem due to a large number of electrical appliances (I connected an electric winch and plugged in a few more lamps). The system couldn't cope. Also, P1602 may appear if you change the battery or when starting the engine on a discharged battery.
2. Generator. The reason may be its power or the fact that the contact disappears. The problem often occurs on Priors, Kalinas and VAZ 2114

1. Signaling. There are modern car protection systems that turn off the battery when the alarm is turned on. It is assumed that if thieves get into the cabin, they will not start the engine. However, the system may generate this exact error.
2. Minor power loss. For example, you start your car in cold weather. A large flow of energy went from the battery to the starter. The controller was left without power for a short time. As a result, the system issued P1602.
3. “Mass” of the controller. The reason is quite common. Your car contact is simply oxidized, and the system thinks that it has been left without power and generates an error.
4. "Mass" between the body and the engine. This happens if your engine is damaged (for example, after an accident), contacts are oxidized, or wire insulation is damaged.
5. Safety block. The wires in them can also periodically oxidize. As a result, the voltage may also drop. Although the block itself is also worth checking, the reason may be in itself.
6. Control electrical unit. The error may also appear due to hardware problems. Then I recommend that you contact the service; if you don’t understand it, then it’s better not to get into the firmware yourself.

Let's remove these annoying numbers from the screen

Without exaggeration, the constant appearance of error P1602 on your VAZ-2114 car can be thoroughly annoying. Sometimes it seems that the car is mocking you, but do not forget that the car does not have its own decision-making center, and this is all on-board computer. Maybe he really has a wicked sense of humor. The simplest way to diagnose its performance is to simply replace one device with a similar one that is known to be working. The only problem may be getting another computer, but you don’t need it forever, you can just borrow it from a friend, simultaneously enlisting his services as an assistant, since he is so generous: what if the breakdown is in the machine, and not in the electronic brains , then extra hands will come in handy. If this error appears very often, you can try updating or changing the computer firmware. To do this, it is better to contact a specialist.

Elimination methods

Methods for eliminating error p1602 directly depend on the reason why it was formed in the memory of the electronic control unit. However, before performing the steps listed below, it makes sense to programmatically reset the error. If there are no visible breakdowns, then it is quite possible that the error “Court Controller, loss of supply voltage” was generated accidentally.

We list possible solutions to the problem in the same sequence as the reasons that caused them:

• Battery. Use a normally charged battery that holds a charge well and also has the appropriate capacity suitable for a particular vehicle (this is especially true for winter, when difficult engine starts are expected). Periodically check the charge level, electrolyte density, the quality of the terminal contacts on the battery, and if necessary, clean and lubricate them. Clean the contacts on the wires in the same way. If possible, you can check the battery leakage current. Sometimes an action that helps get rid of the error is to remove the negative wire from the battery for about 5 minutes (a few seconds is not enough), and then quickly put it on and set it in such a way as to ensure tight contact between the wire and the battery terminal. It is also advisable to first clean and lubricate the contact.
• Generator. It makes sense to double-check the operation of the diode bridge, check the voltage at the terminals (on most modern passenger cars the corresponding value should be about 13.7...14.0 V). Check the ground of the generator and, if necessary, inspect the wire and corresponding contacts. Similarly, clean all accessible contacts on the generator, as well as tighten them. You can also re-stripe the wires and make new contacts to improve their quality. Clean the base of the generator mount and the engine block at the point of contact. In some cases, tightening the alternator belt helps (especially if it slips and whistles); if the belt is significantly worn, it is better to replace it with a new one. In rare cases, the generator is completely replaced.
• Signaling. Regarding the alarm system, it is advisable to consult with the employees who installed the alarm system on the car, or find documentation for it on the Internet and find out whether it disconnects the battery from the system as protection or not. If yes, then you will have to come to terms with this error, or, as a last resort, change the alarm system to another one without a similar function.
• Short-term voltage drop. Usually in this case, this error is simply reset programmatically from the ECU memory. It should not be restored in the future.
• "Mass" of the ECU. Check the quality of the ground; if it is damaged, restore the integrity of the contact and/or wire. The chip may be damaged.
• Ground connection between the body and the engine. Inspect the wires and contact connections; the tips (if any) may be damaged. If necessary, test the wire with a multimeter to check for continuity or damage to the insulation. If the wire is broken or damaged, it must be replaced with a new one. In this case, it is advisable to use tips.
• Fuse box. Check the contacts in the block. Moreover, both coming from the battery and internal ones, directly on the fuses themselves. If necessary, tighten the contacts, remove oxides, and lubricate. It is especially necessary to check the fuse that goes to the electronic control unit, as well as its seat, the quality and cleanliness of the contact, and if necessary, inspect and clean it. It is also advisable to check the condition of the contacts in a special block under the hood. To do this, it is better to use a special contact cleaner.
• Electronic control unit. If there is such a possibility, it is advisable to install an ECU of the same model with the same firmware version on the car. At the same time, check whether voltage is coming to the supply terminal of the control unit and what its value is. However, it is best to seek help from official dealers or a car service that repairs electronic “brains,” since reflashing or changing settings yourself can be fraught with big problems.

As practice shows, error 1602 itself is in most cases harmless, and the car owner finds out about it only when he uses a scanner to remove information from the ECU along with other errors or there is an on-board computer with a screen on which the relevant information is displayed. Therefore, if it does not affect the behavior of the machine (and in most cases this is the case), then the machine can be used and “bothered” about it. As for elimination, the cause is usually poor ground or battery contact.

Good afternoon, we installed a 2016 Lada Vesta starline a93 on a Lada Vesta 2016 car, everything works great, but there is one thing, when you put the car on autostart and then start it again, error 1602 pops up (disconnection of the power supply). We also opened it from the key fob, just without autostart) tell me what could be the problem in the launch module? I checked all the wires several times

Answers 5

Hello. In which block does the error appear?

Have you performed breaks to make the buttons on the standard key work during autostart?

I won’t say which one exactly, the error occurs in the car’s ECU, what are the gaps? The standard key works!

I’ll add a little that starline a93 2can 2 lin

Your profile says “auto electrician”. Have you installed an alarm? Or are there other INSTALLERS?

what kind of breaks? The standard key works!

Breaks in the wiring, in the presence of which the BUTTONS on the car key work AND WHEN THE ENGINE IS RUNNING and the car can be unlocked when it is in AUTO START with the engine running. Is it possible to get into your car by pressing a button on the key if you first start it with the StarLine key fob? If YES, then most likely the very breaks in the wiring that allow you to use the car key in this way (many owners want to be able to get into the car at any time without taking the alarm key fob out of their pocket/bag) were MADE INCORRECTLY. More precisely, the settings of the alarm CHANNELS that control the process of breaking and restoring the car wiring were made incorrectly.

If the buttons on the key do not work when the engine is started via the alarm, then the problem is something else. But in any case, you cannot do without visiting competent alarm installers. If the alarm system is installed correctly, such errors cannot occur in the vehicle’s on-board systems. This means that something was done incorrectly when installing the alarm. We need to fix it. What exactly? You can only find out LIVE by examining what has been done and programmed with your own eyes.

The reason was found: when starting the car, just after the car was set to autostart, a short pulse occurs on the engine blocking wire, which leads to a short activation of the blocking relay

Error 1602 (or correctly P1602) should be understood as “Control system controller, loss of on-board network voltage.” When this error occurs, the controller refers to the electric motor control unit (ECU) (electronic control unit).

When error 1602 appears, it is difficult to determine what exactly is the problem with the unit or device. Therefore, to eliminate it, it is necessary to diagnose the entire system.

Video about fixing the error

Error 1602 is usually harmless. The driver often doesn’t even know about it and only finds out by reading information from the controller (this is if there is no on-board computer with a monitor). Therefore, we can say that in most cases it does not affect the operation of the car and is associated with the fact that somewhere there is a slightly weak contact.

I won't fix it, that's how it works

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What is error P1602

When this malfunction occurs, electrical voltage stops flowing to the motor control unit. There may be two options:

1. There is no voltage in the system at all.
2. Partial lack of power.

Typically, voltage is transmitted to the controller via several buses:

• 30 bus – constant voltage, parallel to the positive terminal of the battery;
• 15 bus - voltage passes through the ignition relay;
• 50 – voltage passes when the engine starts.

In addition, the motor control controller voltage can pass through the ECU contacts.

First of all, you should understand that if the error code is P1602, then there is no voltage in an emergency or this is a deliberate action of the system. Just as I wrote above, there may be no voltage only in certain areas and, as a result, there is no power to the ECU. The problem can arise from almost any electrical mechanism, for example:

• When wires break;
• If the generator fails;
• Relay problems;
• In case of battery failure;
• If you intentionally reboot the system;
• Other.

This error can appear even if you simply removed the negative terminal of the battery.

This does not mean that you should not react to it in any way. An error may make it difficult to start the car. You will especially notice this during the cold season.

Therefore, it is important to find the cause of the error as quickly as possible. Such minor damage can lead to wear and tear of more expensive components.

What does the error consist of?

The first character means:

• B - malfunction of car body elements;
• C - problems with the suspension or chassis;
• P - malfunction of the power and transmission units, as well as the engine control unit;
• U - problems in the operation of information exchange buses.

The second character in the code means:

• 0 - standard SAE type;
• 1, 2 - factory type of fault;
• 3 - reserved.

The third character identifies the system in which the problem is detected:

• 1 and 2 - problems with fuel units;
• 3 - ignition unit and mechanisms connected to it;
• 4 — system for reducing exhaust gas toxicity;
• 5 — idle speed of the power unit;
• 6 - electronic engine control module and wires connected to it;
• 7 and 8 - transmission unit.

The last two characters are a number that corresponds to the error number in the OBD system.

When malfunctions occur in the operation of the engine or other systems, the “Check Engine” indicator is always on on the VAZ dashboard. Its presence may be due not only to a malfunction of the power unit, but also to problems with the wiring or poor contact of one of the sensors.